F.1 Math (急急急10點)

2008-12-28 2:40 am

Find the values of the 4th term X and 8th term of the sequence 1,4,16,X,256,1024, ...

超急~~

更新1:

比條"色" 例如:5n+1 A1=5n+1 =5(1)+1 =6 A2=5n+2 =5(2)+2 =12 6,12,18,24,30,36,42.....

更新2:

一定有一條"色"先可以計出1,4,16,X....

回答 (6)

2009-01-02 3:31 am

The formula is:

nth term = 4^(n-1)

4th term = 4^(4-1) = 4^3 = 64

8th term = 4^(8-1) = 4^7 = 16384

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2008-12-28 9:31 pm

E個5可以說明是平方數,because no 9 in it, it is某數的X次方乘1
1=1
4=1x4
16=1x4x4
X=1x4x4x4=64
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.
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Y=1x4x4x4x...x4(Z個4)

參考: me俾分我俾分我俾分我俾分我俾分我.............................................................!

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2008-12-28 3:23 am

the general term is
4^(n-1)

find the 4th term
when n= 4
4^(3)=64

8th term
= 4^7 =16384

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2008-12-28 3:17 am

1,4,16,X,256,1024, ...

1=1
4=1x4
16=1x4x4
X=1x4x4x4=64

So,An=4^n

參考: need not to know

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2008-12-28 2:51 am

x係64
第8項係4^7次=16384

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2008-12-28 2:50 am

1,4,16,64,256,1024,4096,16384,65536,262144,1048576.............
4th:64 8th:16384

2008-12-29 10:27:52 補充：
4th:1x4x4x4=64

8th:1x4x4x4x4x4x4x4=16384

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